Frank j



F. J. ROOT."

ART OF TREATING COAL. APPLICATION FILED APR. 7, 191's.

1,426,012. Pa ented Aug. 15, 1922.

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wer stare srartm orrics.

FRANK a. noon on onioneo, ILLINOIS. 1

Aaron TREATING Conn Specification oi Letters Patent. Patel/111.3 1 A 15 2 Application filed April 7 1919. 'S erial'No. semestfrom as commercial products the substances derived by the carbonization or composition thereof. i

In processes involving he-application of thermal deheat to coal a proper control'ofthe tempera ture is of great importance, inasmuch as the products obtained vary in character with" the temperature conditionsprevailing in the treated coal. The character of both the primary and secondary products of decomposition are dependent upon thetemperature of treatment, and this may-vary in different portions of the coal under treatment inac cordance with certain factors, among 'Which the most important are the density and conductivity of the coal, and the uniformity of heating of the mass. Other factors Which affect the character more particularly of the secondary products of decomposition, such as the'tars, are the length and the thermal characteristics of the passages atforded for the passage of the v'apors and gases generated, and their proxim ty to the heated Walls of the retort container. Thus,

When a body of coal is placed in Iachamber or retort and heat is applied fro nlthe ere,

tei'ior the rate at Which the interior becomes heated will depend upon the conductivity o'l the charge, as Well asupon the external temperature applied, and the conductivity oit'the charge will vary largely with its compactness and the proportion of inter spaces in the charge. Hence Witlra low conductivity chargeihaving a high 'propora tion'of interspaces, such asthose now in use, a high temperature decomposition re sulting in a relatively high proportion of cyclic and aromatic compounds Will talre place in the outer portions of the charge,

While Withinthe charge low temperature decomposition Will be e'filectech'a relatively I high proportion oit'aliphatic and naphthene compounds being formed. it is also apparentthat if the retort shape and charge arrangement is such that the vapors formed pass through a relatively cool port on or the charge; (the interior) any secondar decompositions Which take place will be iargelyinto aliphatic and naphthene com- "pounds, Whereas if the vapors pass through a more highly heated portion of the charge (the outer layers, for example) a larger proportion of aromatic compounds Will be I formed in their secondary decomposition.

It is hence apparent that a proper control of conditions ithin the retort With the properapplication of heat are necessary for securing economically and ci'hciently the products desired by the operator in treating the coal. I

- in'a'ccordance With my present invention, I subject the coal to be treated, compacted toga greater or less extent, "to the" action. of heat under conditions such that the primary and secondary decompositions occur ring may be controlled in accordance with the products desired. The coal, previously coinniinutedand, if desired, admixed with a binder, is n my present process compressed into blocks of great compactness and density and of uniform size'an'd'may be maintained in their compact state during vcarbonization or heat application by maintaining pressure upon themduring the process. the-use of highly compacted material the conductivity of the material is increased and when subjected to heat, particularly under the conditions hereinafter described, the uniformity of the heat decoinpositioneffected and of the resulting products is greater and their character under more perfect control.

The compacted coal utilized in the practics of this process maybe prepared by means of any suitable compressing or briquetting machine, for example, one of the style shown in U. S. Letters Patent No. 953G374, granted to Duryea and White,

January 8, 1911." A suitable form for the compacted coal is of blocks or briquets in the form of short cylinders of circular or elliptical cross-section compressed under a pressure of at least threetons per square inch and preferably of eight or ten tons persquare inch.

vIncarrying out the present process, for example, with compacted coal in the form of short cylindrical briquets, the latter are charged'into tubular'retorts of suitable refractory material in close contact With each other, the retort being of such form as-to permit of a considerable contacting surface with the contained coal and of such size as to provide space for the passage and escape of the vapors and gases formed in the distillation. process. Thus for coal briquets having a diameter of 4 to 5 inches and circular in cross section, a tubular retort, havinga like cross sectionof 6 inch diameter, will provide an adequate contact surface and vapor passage. To secure uniformity of heating itis advantageous that the briquets should not exceed 8 to 10 inches in diameter. lihen arranged in the retort the briquets will form a substantially continuous cylinder against the wall of the retort. To maintain the coal in the compact state during the process of distil a-tion, a continuous pressure may be maintained thereupon. for instance,

by the use of plungers, the plungers being constantly under the action of We I springs or hydraulic pressure. )le means may be provided for the removal of products of distillation from the retort. and for their conveyance into mains and to suitable apparatus for separation into their various constituents. By reason of the 'compact state of the cool .i ass it is very rapidly penetrated by the heat and being in cylindrical form it will, in a very short space of time, have a practically uniform temperature throughout. effectan elongated cylinder, is constantly under applied pressure, a high density of the material is maintained and consequently a high conductivity and a greater unifornr ity of temperature throughout are likewise maintained. Furthermore, to secure a determined. average temperature throughout the body of coal, it is not necessary to apply an external heat as much higher than the desired temperature is the case in present processes of coal carbonisa-tion and distilla tion. As it appears that there is not so great a difference between the external temperature and the internal temperature of the retort, in the present process the temperature to which the gases and vapors are subjected in their passage through the retort is substantially uniform throughout and not substantially different from that of the coal mass from which they have just generated. A uniform heating effect appears thus to be the result both in the coal mass and in the vapor and gaseous bodies in the retort, both being readily under the control of the operator by a proper regulation of the external heat.

In carrying out my process, I control the temperature applied to the retort in accordance with the character of the product which it is desired to obtain and the character of the coal which is treated. Thus if it is desired to produce what is known as a smokeless coal from a bituminous or semi-bituminous material, I apply to the retort an external heat of lOOi-.5O C. The coal brie As the coal mass, which is in quets acquire a temperatiu'e approximating the external temperature 01' the retort, and this temperature substantially uniform throughout the retort, a removal of the volatile matter or" the coal is rapidly effected and without substantial or undue decomposition.

In production and by-product coking 1 may use higher temperatures, the specific temperature utilized varying. in accordance with the character of the produc desired. in general it may be stated that if it is desired to produce a by-product containing a relatively high proportion of aromatics, temperatures of L000 or above should be used. As is readily apparent, in the proseut process. it is not necessary that the es:-

taat usually applied in gas manufacture and conductivity of the coal mass and the retort result in a more rapid penetration o the interior of the coal mass by the heat, a gixater llllll.\ ll u* in the products of dis tillation produced in various parts of the retort and .t more adequate control of the character of the products.

in carrying out the present process as applied to the carbonization oi? coal wherein a temperature oi? from i00 to 450 C. is applied for the purpose of producinga nonsmokingluel, we may utilize retorts of cast iron or steel. illustrated in the accompanyinc drawing. which shows in section apparatus adapted to carry out such an applicaot the present process.

n the drawing is illustrated in section a nae-e l of refractory material, provided with suitable heating means. illustrated as a lire to 2, and with a suitable exit 3 for t..e waste products of combustion. Within the furnace, and preferably extending therethroug are a plurality of tubular retorts 41-, which may suitfily be of circular cross-sec tion. in the utilization of the process for the production of a non-smoking coal, for which temperatures of 400 to 4-50 C. are required, the retorts may suitably be con stri-ictcd. of iron or steel. At one end of the furnace the retorts open into a suitable chamber 5, from which an exit passage L uniformity of temperaturethroughout the- F sulting from the carbonization of the coal. This chamber is closed from the exterior by means permitting access to the interior of the chamber and the retorts. This is indicated as the door 20 attached to the furnace or to the chamber 5 by suitable hinges 7 and locked i' orexaniple, by the cam locks S.

The coal briqucts are placed in the retorts ml temperature applied be as great as lid is provided to carry away the products rel, the door being open and are so arranged as to term a substantially continuous column or cylinder in the retort. The diameter of the briq iets is less than that of the retort,

so as to provide a suitable vapor passage between the retort and th ibliqllet? T of a diameter preferably less than that of the briquets, which enter the retort end and are removably retained in position by any suitable means, such asthe screws 11, which pass through the door 20. 'i I r in order to exert pressure upon a the column of briquets in the retort, or to maintain said column against expansion, I may provide plungers 12, provided with rods 13, which extend through suitable stuffing boxes 14 in the caps 15 of theretorts at the ends opposite their charging and discharging ends. The pressure upon the plungers may be exerted by any desired means, such as weights, springs or hydraulic pressure. In the present embodiment it is applied by means of weights 16, which are attached to the rod 13 by means of cables 17 passing over pulleys 18 mounted on the furnace wall. It is obvious that where it is desired only to prevent expansion of the column of coal briquets in the retort, the plungers 12 may be locked in position and theweights l6 dispensed with. It has been found, however, that advantageous results are secured by maintaining a constant pressure upon the material during the process; forexample,

with retorts containing briquets' l-jto 5 inches in diameter, a weight of 100 tol20 pounds has been found to produce a well compacted residual coal-like product or nonsmoking fuel. With Illinois coaland utilize ing a maximum temperature of approximately 450C, 77% of the original weight of the fuel was found to remain in the coke The column of like product in the retort. coal is heated substantially uniformly throughout its length and, by reason of its high conductivity, the thermal conditions are substantially uniform throughout its thickness.

Art the termination of the carbonization of the coal, for this purpose, which maytake place in from 2,} to 3?} hours, the retort may be discharged by ,Eopening the doors 20, thereby removing the plungerslO and forcing the plungers 12 through the retorts to eject the residual material. I I

In utilizing the process for the production of gas, or for by-product coking, it will be readily apparent to those skilled in theart that retorts of suitable refractory material may be utilized and the te'mperatureandtime of treatment controlled in accordance with the character of the decomposition desired. The conditions suitable for thevarious'types of decomposition of the coal have already. been set forth in the specification.

The volatilized decomposition products will pass, off through the passageway between the column of briquets and the retort walla-being subjected to substantially uniform thermal conditions throughout, and willbe conducted to suitable separating and purifying devices by pipe 6.

- Although I have described my invention in connection with certain theories as to the operation thereof, and have also described certain specific embodiments thereof, I do not intend that the scope of my invention shall be limited by the accuracy of the theories set forth, nor to the specific details recited, ex

cept in so far as such limitations are includv ed in the accompanying claims.

I claim:

1. The process of treating coal by the ther mal decomposition thereof, which consists in compacting the coal to a dense block, subjecting the same to, the action of heat, applying pressure thereto in one direction, the dense mass being surrounded by a retort of greater size than said body transverse to the direction of application of pressure.

2. The process of treating coal by thermal decomposition thereof, which consists in compressing the coal into compact blocks, subjecting a plurality of said blocks, juxtaposed in the form of a column, while surrounded by a retort of greater cross section than said column, to the action of heat.

3. The process of treating coal by thermal decomposition thereof, which consists in compacting the coal into dense blocks, sub jecting a plurality of said blocks, juxtaposed in the form ofa column, while surrounded by av retort of greater cross-section than said column, to the action of heat, and

" reventin lon itudinal ex )a-nsion of said column.

4:. The process of treating coal by thermal decomposition thereof, which consists in compacting the coal into dense blocks, subjecting a plurality of said blocks, juxtaposed in the form of a column, while surrounded by a retort of greater cross'section than said column, to the action of heat and applying pressure to said column longitudinally thereof.

5. The process of treating coal by the thermal decomposition thereof, which consists in compressing coal particles by a pressure of at least three tons per square inch into dense blocks, subjectingsaid blocks in the form of a continuous column, while surrounded by a retort of. greater cross section than said column, to the action of heat applied throughout the length of the column. I 6. The process of treating coal to produce a smokeless fuel therefrom which consists in compressing coal particles into dense masses by a pressure of at least three tons er square inch and subjecting the dense mass :to a temperature of 450 C. uniformly app-lied throughout. 7 I

7. The process of treatingcoalto produce a smokeless fuel therefrom which consists in compressing coal particles into clenseb'locks by a pressure of at least three tons per square inch, applying pressure to said blocks in one dlrectlon While sub eCtmg it to a teinpera- 1O 'ture of 450 0., the blocks being surround- FRANK J. ROOT. 

